Hot top with dead air space



Nov. 9, 1965 R. E. DALEY HOT TOP WITH DEAD AIR SPACE Filed Jan. 24, 1963 lllllllllll |l| 1' w HI WHH I IUH I I MMH- 1! 7 mmmmn u wmw n m i 4: n .6 Mb .M Y ZULU 6 W, 1m W :LI. 3 WM II\\\\QI\\ d n... /A 3 INVENTOR ROBERT E. DALE) A TTOR/VEVS.

United States Patent 3,216,683 HOT TOP WITH DEAD AIR SPACE Robert E. Daley, 8355 Remington Drive, Pittsburgh 37, Pa. Filed Jan. 24, 1963, Ser. No. 253,693 6 Claims. ((Il, 249197) This invention relates to ingot mold hot tops, and more particularly to insulating the molten metal in the hot tops from the hot top casings.

The usual hot top consists principally of a refractory-lined metal casing provided with a large central vertical passage through which molten metal is poured inot the ingot mold on which the hot top is mounted. Pouring is continued until the molten metal rises in the hot top to form a reservoir or sink head that will sink into the mold as the metal in the latter cools and con tracts. To make sure that a shrinkage cavity will not be formed in the upper end of the ingot due to soliditying of the molten metal in the hot top before the metal below it has solidified, it is the practice to use a large sink head so that there will be sufficient mass to keep the central core of the sink head molten until everything below it has set. The result is that for each pour a considerable amount of metal is wasted in the sink head that has to be cropped from the ingot.

It is among the objects of this invention to provide a hot top which will insulate the molten metal therein so well that the size of the sink head can be reduced materially, and in which insulating members can be quickly installed and replaced.

In accordance with this invention the .hot top metal casing, provided with a central vertical passage, is lined in the usual way with refractory material, but in addition to this lining insulating panels are mounted in the casing in positions spaced inwardly from the lining to create between the lining and the panels dead air space. Preferably, the panels are held in place by upright retaining members at their vertical edges and by a flange or bottom ring at the base of the hot top casing.

The preferred embodiment of the invention is illus. trated in the accompanying drawings, in which FIG. 1 is a plan view of my hot top with a portion of the upper flange broken away;

FIG. 2 is a combined vertical section and side elevation taken on the line IIII of FIG. 1;

FIG. 3 is a fragmentary enlarged vertical section of the hot top taken on the line IIIIII of FIG. 1; and

FIG. 4 is a fragmentary horizontal section taken on the line IV-IV of FIG. 3.

Referring to the drawings, the metal casing 1 of a hot top has an inwardly projecting ledge 2 at its lower end, which supports the usual refractory lining 3 that engages the inner surface of the side wall of the casing around the large vertical passage 4 through the casing. This passage preferably is substantially rectangular, having four sides but preferably diagonal corners. At the top of the casing there is an inwardly projecting flange 6 that may be integral with the rest of the casing or secured to it by stud bolts 7 as shown. This flange forms a part of the metal casing and extends inwardly over and past the refractory lining. The metal casing may rest on a refractory bottom ring 8 that may be attached to the casing in any well-known manner, such as by wire clips 9. As shown in FIG. 2, the ring may be seated .on a gasket 10 mounted on top of an ingot mold 11, or the lower part of the hot top may be inserted in the upper end of the mold. The bottom ring extends inwardly from casing ledge 2 to about the same extent as top flange 6.

To retard cooling of molten metal in the hot top for 3,216,688 Patented Nov. 9, 1965 a much longer period than has been possible heretofore, additional insulation is provided between the metal and refractory lining 3. This insulation takes the form of replaceable insulating elements and dead air space. Ac cordingly, at least four upright insulating panels 13 are mounted in the hot top casing and are spaced from its 7 lining. The panels may be made of the same retractory as the lining, but preferably they are made of a lightweight refractory, such as expanded slag or expanded shale, so that they are lighter and more insulating than otherwise would be the case. The panels are located at all four sides of the hot top passage and may rest on the bottom ring, or on bottom ledge 2 if it is wide enough and top flange 6 is removable. Their upper ends are covered by the top flange, which it is best that they engage. One way of spacing the panels from the hot top lining is to provide their backs at their opposite vertical edges with integral vertical ribs 14 that engage the lining. To hold the ribs against the lining and thereby hold the panels in place, upright retaining members are mounted in the corners of the vertical passage.

Preferably, each of these retaining members is a vertical bar 15 that may be made of the same material as the panels. The bar extends diagonally across a corner of passage 4 and its opposite sides are provided with vertical channels 16 that receive and overlap the adjoining marginal portions of two of the panels and thereby prevent them from moving away from the refractory lining. The back of each bar may engage the refractory lining also, but the back is provided with a verti cal channel 17 to form a dead air space. If desired, the ribs 14 on the backs of the panels can be eliminated if the sides of the retaining bars are provided with vertical slots for holding the edges of the panels. When the hot top passage is extremely large, it may be desirable to provide the central portions of the panels with ribs to engage the surrounding lining.

In order to insert the insulating panels in the hot top casing shown, it is turned bottom side up without the bottom ring 8 in place, and the retaining bars 15 are lowered into the corners of the casing until they rest on flange 6. To properly position the bars, their lower ends may be provided with vertical holes 19 to fit down over metal pins 20 (FIGS. 1 and 3) projecting upward from the upper surface of the inverted flange. After the bars have been inserted, the panels 13 are lowered into the casing between its lining and the laterally projecting portions of the bars that overlap the inner surfaces of the panels. Ribs 14 engage the lining and space the panels from it. With all of the bars and panels in place, the refractory bottom ring is placed on top of the inverted casing and connected to it by the clips 9. To help prevent the panels from being bent outwardly by the molten metal poured into the hot top, the bottom ring can be provided with a continuous rib 21 that will project into the space between the casing ledge 2 and the panels and serve as a spacer. A similar rib 22 may be formed on the inner surface of flange 6 for the same pur- .pose. In such cases, the ribs 14 on the backs of the panels will be shorter than the panels themselves, and the bar ends will be provided with cut out portions to receive the bottom ring rib and flange rib. After the bottom ring has been mounted in place, the hot top is turned right side up again and is ready for use as shown in FIG. 2.

It will be seen that between every panel and the surrounding lining there is a dead air space of large area that contributes materially to insulating the hot metal in the hot top from the relatively cool metal side walls of the casing. As a result, less metal is required for the sink head so there is less loss per ingot by cropping. Furthermore, the metal thus saved in pouring a number of ingots may be enough to pour an additional ingot.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A hot top comprising a metal casing provided with a central vertical rectangular passage therethrough for molten metal, a refractory lining in the casing, separate upright insulating panels spaced inwardly from the lining along all sides of said passage, upright retaining members at the corners of said passage overlapping the adjoining inner vertical edges of the panels to hold the panels upright, whereby an air space is formed between each panel and the lining, and means closing the top and bottom of said air space.

2. A hot top according to claim 1, including means for holding said retaining members in place before insertion of the panels.

3. A hot top comprising a metal casing provided with a central vertical passage therethrough for molten metal and with an inwardly projecting flange at its upper end, a refractory lining in the casing, separate upright insulating panels beneath said flange and spaced inwardly from the lining with their upper ends close to the bottom of said flange, and a refractory bottom ring beneath said casing and attached thereto, said ring projecting inward beneath said panels and supporting them, whereby dead air space is created between said lining and panels the bottom ring being provided with a top rib projecting up into said air space substantially in engagement with the panels.

4. A hot top comprising a metal casing provided with a central vertical passage therethrough for molten metal and with an inwardly projecting flange at its upper end,

a refractory lining in the casing, separate upright insulat- 40 ing panels beneath said flange and spaced inwardly from the lining with their upper ends close to the bottom of said flange, upright retaining bars between the edges of adjacent panels and overlapping the inner surfaces of the panels to hold the panels upright, the upper ends of the bars being provided with vertical holes, pins connected with said casing and projecting down into said holes, and a refractory bottom ring beneath said casing and attached thereto, said ring supporting said bars and panels.

5. A hot top according to claim 4, in which each retaining bar has a pair of laterally spaced portions extending vertically and engaging said refractory lining.

6. A hot top comprising a metal casing provided with a central vertical rectangular passage therethrough for molten metal and with an inwardly projecting flange at its upper end, a refractory lining in the casing, a separate upright insulating panel at each side of said passage provided with vertical ribs spacing it from said lining, said flange being provided with a bottom rib projecting down between the panels and lining substantially in engagement therewith, upright retaining bars at the corners of said passage engaging said lining and overlapping the adjoining inner vertical edges of the panels to hold the panels upright, and a refractory bottom ring beneath said casing and attached thereto, said ring projecting inwardly beneath said bars and panels and supporting them, whereby dead air spaces are created between said panels and lining.

References Cited by the Examiner UNITED STATES PATENTS 1,425,658 8/22 Jamison.

1,573,313 2/26 Giesey.

1,804,206 5/ 31 Charman et al.

1,830,479 11/31 Mueller.

1,969,726 8/ 34 Charman.

2,046,043 6/36 Urmetz.

2,821,000 1/58 Nouveau.

2,822,591 2/58 Hampe.

3,178,783 4/65 Edsell et a1. 249-106 J. SPENCER OVERI-IOLSER, Primary Examiner.

ROBERT F. WHITE, Examiner. 

3. A HOT TOP COMPRISING A METAL CASING PROVIDED WITH A CENTRAL VERTICAL PASSAGE THERETHROUGH FOR MOLTEN METAL AND WITH AN INWARDLY PROJECTING FLANGE AT ITS UPPER END, A REFRACTORY LINING IN THE CASING, SEPARATE UPRIGHT INSULATING PANELS BENEATH SAID FLANGE AND SPACED INWARDLY FROM THE LINING WITH THEIR UPPER ENDS CLOSE TO THE BOTTOM OF SAID FLANGE, AND A REFRACTORY BOTTOM RING BENEATH SAID CASING AND ATTACHED THERETO, SAID RING PROJECTING INWARD BENEATH SAID PANELS AND SUPPORTING THEM, WHEREBY DEAD AIR SPACE IS CREATED BETWEEN SAID LINING AND PANELS THE BOTTOM RING BEING PROVIDED WITH A TOP RIB PROJECTING UP INTO SAID AIR SPACE SUBSTANTIALLY IN ENGAGEMENT WITH THE PANELS. 